This invention relates to an improved system for initializing a position sensor for an engine actuator. More particularly, this invention relates to initializing an incremental position sensor based upon the last know location of the sensor.
Intake manifolds control airflow into a vehicle engine to modify engine performance. Engine actuators are used to control valves within the intake manifold. The valves modify air flow characteristics to enhance engine performance in terms of either fuel economy or torque output. A sensor measures the rotational position of an engine actuator output shaft to determine the position and speed of the valves. The position information is sent to an engine controller which uses the information to adjust the valves. Absolute and increment position sensors are utilized for determining the engine actuator speed and position.
Currently, to provide accurate information the increment sensor must be initialized each time the system starts. The system does not know what position the increment sensor is at start up. The sensor must be moved to a known location prior to normal operations. Known systems rotate the output shaft to move the sensor and valves back to a default start or zero position prior to beginning normal sensor operations.
However, moving the sensor and valves to a default position can create undue movement of the sensor and valves and provides little information to the system regarding the sensor assembly. It is therefore desirable to develop and design an improved arrangement for initializing a position sensor to provide feedback to the system.